adj
crazy
KRAY-zee
adj
1
Mentally unstable or irrational; behaving in a wild or nonsensical way.
"It would be crazy to quit your job without any savings."
"He went crazy trying to fix the printer for the third time that day."
2
Informal: extremely enthusiastic about or infatuated with someone or something.
"She's crazy about horror movies."
noun
1
Informal: an eccentric or irrational person.
"Don't listen to him, he's just a crazy."
How to Use Crazy
Learner’s notesIn plain EnglishWildly irrational, or (informally) very enthusiastic or infatuated.
When to use it
Very common in casual speech; avoid in clinical or formal contexts describing actual mental illness, where it can sound dismissive.
Common pairings
crazy about
drive someone crazy
go crazy
Word Forms
crazier comparative, more crazy comparative, crazies plural, craziest superlative, most crazy superlative
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Etymology
From craze ("to crack or shatter") plus -y — the idea of a mind that has "cracked" led to the modern meaning of insane or wildly irrational.